CDRIVER-208 [undo] mongo_cursor_get_more has invalid free of cursor->reply
fix memory leaks found by valgrind
fix remaining memory leak found by valgrind
fix uninitialized memory error found by valgrind
fix another uninitialized memory error found by valgrind
CDRIVER-214 Fixed memory leak in mongo_replica_set_client
write_concern_finish test
CDRIVER-210 Tailable cursor set cursor invalid
Merge pull request #5 from mongodb/master

Merge update from mongodb:master